1. Field of the Invention
This invention relates to an air cleaning device for internal combustion engines, having a back flow gas shut-off function, wherein a back flow gas check valve is provided in an air induction pipe connected with a cyclone type dust collection device and the closing of said valve serves to stop the application of high voltage.
2. Brief Description of the Prior Art
Hitherto, this type of air cleaning device for engines having such a back flow gas shut-off function has not existed in the known art. The air cleaner for engines, employing an electrostatic filter, has a very high dust collection efficiency and also high marketability and mass productivity.
However, the discharge wire or plate is applied with as high a voltage as possible to charge dust in the atmosphere with electricity, so that sparking discharge may occur between the positive and negative poles when the insulation between them deteriorates.
As a result, there is the danger of explosion if the engine induces backfire and the mixed fuel gas flows back from the carburetor located near the manifold into the electrostatic filter through the air induction pipe.